岩魚坊主
いわなぼうず

Translation: char priest
Habitat: mountain streams
Diet: carnivorous

Appearance: Iwana bōzu are enormous iwana (char, Salvelinus leucomaenis), a kind of river fish, that have turned into yōkai. They walk upright on two legs like humans and dress in Buddhist priest robes. They are found by mountain streams where people fish for iwana and other river fish.

Behavior: Iwana live in rivers and streams high up in the mountains. Iwana which survive for many years and grow to an enormous size become iwana bōzu. They learn to transform into human shape, leave their rivers, and even speak.

Interactions: Iwana bōzu appear out of nowhere and ask people who are fishing to stop and go home. They usually approach people catching more fish than they need to survive rather than those who are just feeding their families. In particular, they target those who use extreme measures of fishing, such as poisoning the river with Japanese pepper (Zanthoxylum piperitum), which causes fish to float to surface and makes them easy to catch. They lecture about refraining from needless killing, and taking life only when it is necessary to survive, and so on. Because they dress and speak in a manner that resembles a Buddhist priest, they are usually not immediately recognized as yōkai. It is only until later, after departing, that something seems off or strange and you realize that the person you thought was a priest was in fact a yōkai.

Origin: Iwana bōzu stories can be found in all parts of Japan. In some areas, other fish species such as yamame (Oncorhynchus masou masou) and unagi (eels, Anguilla japonica) are also said to transform into people and admonish humans against cruel and excessive fishing. These stories vary in several details but all follow a similar narrative pattern. Common to all of them is the ending, in which the fish is killed and cut open, the contents of its stomach revealing its yōkai nature.

Legends: Long ago in Gifu, several young men were fishing by a stream. They were using poison techniques to catch a large quantity of fish. While they took a break for lunch, a Buddhist priest with a shiny bald head suddenly appeared out of nowhere and approached the group. The priest asked the young men if they were fishing with poison.

The young men replied that yes, they were using poison.

The priest asked them to stop fishing in that manner. It was a bad way to fish. It was cruel, and it caused excess death, which is a sin.

The young men protested that they had their own livelihoods to think of. But the priest persisted, and admonished them not to take unnecessary life. Eventually, out of politeness, they agreed to stop fishing with poison. The priest seemed satisfied, and the young men offered him some dango to eat. The priest gratefully accepted the food and then left.

After they finished lunch, the men went back to fishing. Despite what they had told the priest, they had no intention to stop using poison. Suddenly, the largest fish they had ever seen—over 180 cm in length—appeared in the river! They threw more and more poison into the river and were able to catch the giant fish.

Gleefully, the young men returned to their village laden with a huge catch. They decided to make a feast of the giant fish. As they prepared the fish, they cut open its stomach and out tumbled the dango that they had given to the priest!

The young men were so frightened that not one of them was willing to eat the fish.